National Ambient Air Quality Standards for Ozone

Document Headings Document headings vary by document type but may contain the following: the agency or agencies that issued and signed a document the number of the CFR title and the number of each part the document amends, proposes to amend, or is directly related to the agency docket number / agency internal file number the RIN which identifies each regulatory action listed in the Unified Agenda of Federal Regulatory and Deregulatory Actions See the Document Drafting Handbook for more details. Environmental Protection Agency 40 CFR Parts 50 and 58 [EPA-HQ-OAR-2005-0172; FRL-8544-3] RIN 2060-AN24 AGENCY: Environmental Protection Agency (EPA). ACTION: Final rule. SUMMARY: Based on its review of the air quality criteria for ozone (O 3 ) and related photochemical oxidants and national ambient air quality standards (NAAQS) for O 3 , EPA is making revisions to the primary and secondary NAAQS for O 3 to provide requisite protection of public health and welfare, respectively. With regard to the primary standard for O 3 , EPA is revising the level of the 8-hour standard to 0.075 parts per million (ppm), expressed to three decimal places. With regard to the secondary standard for O 3 , EPA is revising the current 8-hour standard by making it identical to the revised primary standard. EPA is also making conforming changes to the Air Quality Index (AQI) for O 3 , setting an AQI value of 100 equal to 0.075 ppm, 8-hour average, and making proportional changes to the AQI values of 50, 150 and 200. DATES: This final rule is effective on May 27, 2008. ADDRESSES: EPA has established a docket for this action under Docket ID No. EPA-HQ-OAR-2005-0172. All documents in the docket are listed on the www.regulations.gov Web site. Although listed in the index, some information is not publicly available, e.g., confidential business information or other information whose disclosure is restricted by statute. Certain other material, such as copyrighted material, is not placed on the Internet an…